Focusing device for cinematographic and photographic view-taking apparatus



July 26, 1927.

FOCUS ING DEVICE FOR 1,636,736 A. L. V. C. DEBRIE CINEMATOGRAPIIG AND PHOTOGRAPHIC VIEW TAKING APPARATUS Fi-led April V12, 1926 2 Sheets-Sheet 1 f Y 27m/@n for July ,26' 1927' A. L. v. c. DEBRIE FOGUSING DEVICE FOR CINEMATOGRAPHIC AND PHOTOGRPHIC VIEW TAKING APPARATUS Fild April 12, 192e 2 Sheng-Sheet 2 Patented July :216,1 19l2'7. I

UNITED STATES 1,636.136' PATENT' OFFIQE..

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roousnm nnvrca ron cmnnalroemirnrc mn rno'roemmc vmw-raxnre arrana'rus A Application lied April 12, 1988,'Seria1 le. 101,512, and inllrance April 85, 1925.

It is necessary when a photogra'h and especially a series of cinematograp 1 c pictures are being taken that the focusm of the apparatus should be proceeded with;

many arrangements' have been proposed 1n view of providing for this operation, but none have yet proven satisfactory elther because theyappear as rather intricatel mechanical arrangements or else because they do not answer perfectly all the requirements of a Vsuitable working as they require for instance a setting for each view or show some other drawback. Y v The present invention has for its objectA a.

mechanically very simple focusing device which is of a ve easy handling.

The whole oft e device can' rotate round its axis for instance inside a stationary collar which is secured to the support of the device and which bears an object-glass-holding plate; this plate can be a turret of the known type on which are disposed a`- number of different object-glasses. The rotation of the device allows when the focusing-is to be proceeded with, a rough lass to be brought'in place of the view ta 'ng aperture. This glass can be examined through a magnifying glass also secured to the rotating partand the frame of the rough glass can be, if necessary, rotated through a suitable arwork so as to be brought in exact coincidence as to direction with the location of the view taking aperture. n'

It can also be of interest to follow the scene whilst the ictures are being taken so as to watch the ocusing as well as the setting of the pictures. In view lof this the object-glass-holding plate is provided as known in the art. with two object-glasses or with several sets of two object-glasses in case the late is made up as a turret) one of which is disposedyin front of the location of the view taking aperture'and the `other in a front of the plositionl occupied by the rough glass whilst t e views are being taken; these two object-glasses can both slide as is well known in the'art in a socket and are secured to ther so asto rovide for the simultaneous ocusing with oth object-glasses.

A form of execution ofthe invention is -shown by way of example on appended drawings-whereof: j Fig. 1 is a front view of the wholev device; Fi 2 is a-corresponding lateral cross-section view; I

eparatus 1.

Fig. 3 is a front view of a similar device provided with' a turret or object-glass-holding plate showing the arran ment for simultaneously focusing with t e two objectglasses;

Fig. 4 is a similar view of a modified form of the said arrangement;

Fig. 54 isa partly sectional side view of the arrangement shown on Fig. 4;

Fig. 6 1s a view, similar to Fig. 5 of a modified form of this arrangement. Y

The main part of the view taking ap 4aratus comprising the rear casin thereo 1, the lm and the lm driving mec anism diagrammatically shown at 1', the view taking y aperture 6 and the focusin arrangement described hereinbelow is a apted to rotate round its axis with reference to the objectglass (or glasses) 5 inside a collar secured to the supporting member 3. A plate 4 is 75 secured to the front of the collar 2 and bears the .view taking object-glass 5 dis osed in front of the location of the -view ta 11g aprture during operation. The a paratus 1 1s provlded with a rough glass 7 aving the same size as the aperture 6 and adapted to come when the apparatus 1 is made to rotate round its axis inside the collar 2, into the position occupied normally by this aperture.

To the collar 2 is secured a rack 8 having the shape of an arc of a circle and meshing with a toothed wheel 9 mounted on a socketl10 holding the rough glass and the required screens. This socket 1s' of the same s1ze as the view taking aperture and rotates inside a bearing 11 secured to the body of the a A magnifying lass 12 is dlsposed in alignment with4 t e socket and allows the rough glass to-be examined.

Thus it is evident that when the whole of the apparatus is rotated in thebearing collar 2, the socket 10 rotates round its axis whilst moving along the rack 8. The gear work is calculated so that when the rough glass 7 arrives in theposition normally oc- 100 cupied by the aperture 6, its long and small sides are respectively' parallel to the long and small sides of the "apert-ul'e.. In the form of execution shown on Fig. 1 where the rough lass 7 appears in the position it 106 occuple's w ilst the views are being taken, it 1s necessary that the socket 10 should rotate round its axis a whole number of halfrevolutions whilst the apparatus 1 rotates by the amount necessary for bringing the rough 110 glass-7 in thev place occupied by the aperture 6. I

When the ap aratus is in this latter Ksiv tion the film w ich was originally in of the ob'ect-glass 5 has moved `towards the right of ig. l1 and it is thus an easy matter toexamine and to focus by means of the magnifying glass 12, vthe rough glass 7 and the object-glass .5.

Of course therack and the toothed wheel 9 could be suppressed if the rough glass were set at 180 of the view taking aperture.

In view of allowing the scene to be constantly followed during the view taking, the

plate 4 is providedin front of the location of the rough glass 7 during operation, with a second aperture wherein 1s setthe finder or examining object-glass 13.

The plate 4 can be made u as a turret, which can also rotate with re erence to the bearing collar 2 and' bears a certain number guides. This result 'can be achieved in several manners. A first form of execution is shown on Figs. 2 and 3.

The object-glass 5 is set in a to a socket 14 round which a is .cut and meshing with a worm 15 keyed to shaft 16. To this same shaft is keyed moreover a pinion 17 meshing with a large pinion 18 controlled through the lever 19. In a similar manner, the object-glass 13 isl set in a part secured to a socket 20 round which a helicalrack is cutand meshing with a worm 21 ke ed to the Vshaft 22 to the end of which is eyed a pinion 23 meshing with the lar when t 's' atter the lever 19, the o ject-glasses 5 and 13 are rotated in the same-direction and are pushed by the same amount down their guiding tube whereby their simultaneous focusing is effected. A similar device ma provide'inLa similar manner for the simu taneous Afocusing of the object-glasses 5 and 13.

In the form of execution shown by Figs. 4 and 5 the sockets 14 and 20 ofthe ob'ectglasses 5 and 13 are provided with he ical racks and both engage a worm 24 controlled through the lever. The manner of worklng 1s exactly the Isaine as in the preceding art secured elical rackv imon 18. It canV be seen that y Iimon is rotated through Lastly the object-glasses 5 13 can be .1s in front of the rough glass when the object lass used for the View takin is in front o the exposure aperture. But 1n this case, the object-glasses used respectively for the focusing and flor the view-taking 'have different focal lengths. Therefore if a correct focusing is to be eifected, it is suilcient to provide for a suitable ratio between the movements of the twoobject-glasses in their mounting instead of their being equal asin the' abovementioned case wherein the two glasseshave ual lengths: whatever the kind of mountin t ey are set in, whether threaded or helica gear or rod controlled the ratio between the movements ofthe glasses should be equal to the ratio between the focal lengths.

The abovedescribedv forms of execution can be used also in this case: gear wheels and worms of dilferent pitch may be used or else on the contrary gear wheels and worms of equal pitch may be used in combination with object-glass mountings which show either slopes or threads calculated in view of making the simultaneousgmovements of the glasses' considered allow constantly a correct ocusing for both gl .This arrangement allows not )only the scene to be observed whilst the view taking Vis being proceeded with; but in a great num- -ber of cases it is s'ucient to provide for the initial focusing, without the rotation of the whole apparatus b einv necessary; it can be used even with `view ta g apparatus which are not devised for rotating round their axis.

What I claim is:

1. A focusing device for cinematographic and photographic view taking ap aratus comprising a su porting collar, a te se cured to same, o ]ect l secu to said plate, a view taking device-adapted to rotate around its axis in said collar and provided.

with a view taking aperture a rou h glass secured to the said device an paralll to the plane of the said aperturefthe said aperture and rough glass being at the same distance from the axis of the device asl the object gl device for cinematographic and photographic view taking apparatus com- Y prismg a supporting collar, a plate secured to am, duw-slm wund to anidride 1,ese,7ss

a vewtakingdevice adapted to rotate round its axis in said collar and provided with a view taking aperture, a toothed frame pivotally secured to same, a lrough-glass set in said frame, a circular rack round the supporting collar meshing with the toothed frame, the said aperture and rough glass being disposed at the same distance from the axis of the device as the object glasses, the gear ratio between the frame and the rack being such as will cause the rough glass to have its sides parallel to those of the view taking aperture when it comes in the place normally held by latter.

3. A focusing device for cinematographic and photographic view {taking apparatus comprising a supporting collar, a plate secured to same, object glasses secured to said plate, a View taking device adapted to rotate i roundits axis in said collar and provided with a view taking aperture, a rough glass secured to same and parallel to the plane of said a rture the said aperture and rough glass ing disposed at the same distance from'the axis of the device as the object glasses and finders used for examination purposes set in the abovementioned plate opposlte the location of the rough glass when the aperture is in front of the corresponding object glass.

4. A focusing device for cinematographic and photographic vievv` taking apparatus comprising a supporting collar, a rotating plate-secured to same, object glasses secured to said plate, a view taking device adapted to rotate round its axis in` saidy collar and provided withv a vievv taking aperture, a rough glass secured to same and parallel to .theplane of said aperture, the said aperture and rough glass being disposed at the same distance from the axis of the device as'the object glassesV and finders-used for examination purposes set in the abovementioned plate opposite the location of the rough glass when the aperture is in front of the corresponding object glass, and means for simultaneously focusing eachfinder used for examination purposes vvith the corresponding view taking object glass.

5. A focusing device for cinematographic and photographic view taking apparatusn comprising a supporting collar, a rotating plate secured to same, object glasses secured to said plate, a View taking device adapted to rotate round its axis in said collar and provided With a view taking aperture, a rough glass secured to same and parallel to the plane of said'ape'rture, the said aperture and 'rough glass being disposed at the same disobject glass in view of thel simultaneous o cusing or" both glasses.

6. A focusing device for cinematographic and photographic view taking apparatus comprising a supporting collar, a plate secured to same, object glasses secured to said plate, a view taking device adapted to rotate round its axis in said collar and provided With a view taking aperture, a rough glass secured to same and parallel to the plane of said aperture, the said aperture and round glass being disposed at the same distance from the axis of the device as the object glasses and finders used for examination purposes set inthe abovementioned plate opposite the location of the rough glass when the aperture is in front of the corresponding object glass, a mounting for each object glass and finder provided with a suitably sloped helical rack, a toothed ring engaging said rack and disposed round the kmounting, a control j lever, a worm borne by same and meshing with the toothed rings of the' corres onding finder and object glass.

n testimony whereof I haveaiiixed my signature. l y y y ANDR LEON VICTOR CLEMENT DEBRIE. 

